Using Diet to Lower Cholesterol

~ February 2007 No.212 ~

Concerns about cholesterol are well known. But how much can diet influence serum cholesterol levels? In a well-designed clinical trial carried out in Finland in 2002, 120 previously untreated hypercholesterolemic men aged 35 to 64 years participated in a randomized, controlled crossover trial. Half of the subjects continued with their normal diet; half started eating a "Mediterranean type" diet. Within these two diet treatment groups, subjects received either a statin (Simvastatn) or a placebo. After 12 weeks, those receiving the statin were switched to the placebo, and vice versa. The composition of the diet was designed to reduce energy intake from saturated plus trans-unsaturated fats to no more than 10% by replacing them partly with monounsaturated and polyunsaturated fats rich in omega-3 fatty acids and to increase intake of fruits, vegetables, and dietary fiber.

As expected, in subjects receiving the statin treatment alone had decreased levels of total cholesterol (-20.8%), LDL cholesterol (-29.7%), triglycerides (-13.6%), and increased levels of HDL cholesterol (+7.0%), compared to those not receiving the drug. Subjects receiving the dietary treatment (and placebo - no statin) had decreased levels of total cholesterol (-7.6%), LDL cholesterol (-10.8%), and HDL cholesterol (-4.9%). In addition, the data showed that the effects of dietary treatment and Simvastatin were independent and additive. Taking the statin was beneficial, but if you changed your diet at the same time, you got an even bigger beneficial effect.

The message from this experiment is clear - patients who are prescribed statins to control blood cholesterol levels can help themselves by making changes to their diet. However, the study also contributes to the growing body of evidence that shows the Mediterranean type diet has long-term beneficial effects on heart health.

The Basis of the Mediterranean Diet

1. an abundance of plant-based foods such as fruits, vegetables, bread and other cereals, potatoes, beans, nuts and seeds

2. olive oil as the major source of oil used

3. moderate amount of fish; little red meat is consumed

4. low to moderate amounts of dairy products (mainly cheese)

5. wine is consumed in low to moderate amounts

6. eggs are consumed not more than 4 times a week

Reference

Effects of Diet and Simvastatin on Serum Lipids, Insulin, and Antioxidants in Hypercholesterolemic Men
JMMA 2002,287:598-605